The loading and unloading of large vehicles such as trucks from a loading dock requires that the vehicle be stabilized so as to prevent the vehicle from accidentally rolling away from the loading platform. This can occur, for example, if the driver neglects to sufficiently engage the vehicle brakes, if the brakes fail, or even if the driver inadvertently attempts to drive the vehicle away from the dock prematurely. This can have serious safety and equipment consequences, in that a forklift or other equipment may fall within the gap, or loading dock or other equipment may be damaged. There also may exist regulatory requirements that vehicles be restrained by mechanical means during the loading and unloading process.
A simple method of restraining a vehicle is the use of wheel chocks. However, these rely on consistent operator usage. It is difficult to provide a simple, reliable and practical means to ensure that the chocks have been correctly placed, resulting in the possibility that the dock or truck operator may incorrectly believe that the vehicle has been restrained, when in fact it has not. In response to this drawback, there have been developed various mechanical vehicle restraints which can be permanently affixed to or near the loading dock. Such restraints typically include an arm or other restraining member which moves into a restraining position to engage a portion of the vehicle when the vehicle is properly positioned and parked, and then moves away from engagement with the vehicle to permit the vehicle to depart and a new vehicle to be positioned in its place. Such restraints can be highly effective and less prone to error than wheel chocks. However, existing systems tend to suffer from drawbacks including complexity and cost and the use of components which are not sufficiently robust to withstand the environment of a typical loading dock.
These and other aspects of the prior art are addressed in the present invention.